Synthesis of Half‐Sandwich Tungsten Chlorogermyl and Chlorostannyl Complexes

Abstract

AbstractThe reaction of the dichlorogermane Me2GeCl2 and stannanes R2SnCl2 (R = Me, Bu) with the alkali tungsten salts M[(η5‐C5R′5)L(OC)2W] (L = CO, PPh3; M = Li, Na; R′ = H, Me) yields via alkali salt elimination a range of novel chlorostannyl‐ and chlorogermyl‐functionalized tungsten complexes of the general formula [(η5‐C5R′5)L(OC)2W(ER2Cl)] (R′ = H, Me; L = CO, PPh3; E = Ge, Sn; R = Me, Bu) (3a–e). The use of the phosphane‐substituted tungsten anion Na[(η5‐C5Me5)(Ph3P)(OC)2W] (1c) and Me2SnCl2 leads to a mixture consisting of the mono‐ (3e) as well as the di‐substituted stannyl compound [{(η5‐C5H5)(Ph3P)(OC)2W}2(SnMe2)] (4). Access to 3a is also given by reaction of ClMe2Sn–C5H5 (5) with [(MeCN)3W(CO)3] which includes chemoselective tin shift from the cyclopentadiene to the tungsten atom. In addition, a successive chlorination of [(η5‐C5H5)(OC)3W(SnMe3)] (6) via [(η5‐C5H5)(OC)3W(SnMe2Cl)] (3a) and [(η5‐C5H5)(OC)3W(SnMeCl2)] (7) to [(η5‐C5H5)(OC)3W(SnCl3)] (8) is presented. All new compounds have been fully characterized by elemental analyses and in solution by IR and multinuclear NMR spectroscopy. The crystal structures of complexes 3b–d and 8 were presented and discussed, showing bond lengths of 2.6272(4) Å for Ge–W, 2.7959(5) (3b), 2.7866(3) (3d) and 2.7244(3) (8) Å for the Sn–W bonds.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)